What’s the Biggest Red Flag That a Bike Light Won’t Last?

I don't expect a bike light to survive forever, but some fail way too soon. For me, the first warning sign is a mount that starts loosening after a few rides. After that, it's usually charging port covers that won't stay closed or buttons that stop responding consistently.

Brightness matters, but durability matters more when you ride year-round.

What's the first thing that makes you think, "This light isn't going to last"?